On-chip electromigration monitoring system

A method of detecting when a resistance of a monitored element including a conductive interconnect of a packaged semiconductor chip is over threshold during a lifetime of said packaged chip, comprising:

• using comparison circuitry located within said packaged semiconductor chip, comparing a variable voltage drop across a monitored element including a conductive interconnect of said packaged semiconductor chip with a reference voltage drop across a reference element of said packaged semiconductor chip during a plurality of intervals during said lifetime of said packaged semiconductor chip to detect when said resistance of said monitored element is over threshold.

An apparatus in a semiconductor chip operable to detect an increase in resistance of a monitored element including a conductive interconnect, comprising:

• a resistive voltage divider circuit in said semiconductor chip operable to output a plurality of reference voltages ranging from a first voltage to a second voltage;
• and
• a plurality of comparators in said semiconductor chip, each of said plurality of comparators having a first input and a second input, said first input coupled to receive one of said plurality of reference voltages output by said resistive voltage divider circuit and said second input coupled to receive a monitored voltage representative of a resistance of said monitored element, each of said plurality of comparators producing an output indicating whether said monitored voltage exceeds said one of said plurality of reference voltages so as to precisely determine a value of said resistance of said monitored element.

A method of detecting an increase in resistance of a monitored element including a conductive interconnect of a semiconductor chip, comprising:

• providing a resistive voltage divider circuit in said semiconductor chip operable to output a plurality of reference voltages ranging from a first voltage to a second voltage;
• and
• comparing a monitored voltage representative of a resistance of said monitored element to a plurality of reference voltages to determine whether said monitored voltage exceeds one or more of said plurality of reference voltages so as to precisely determine a value of said resistance of said monitored element.